A segment of the human population has some malformation of the nasal passages that interferes with breathing, including deviated septa or inflammation due to infection or allergic reactions. Part of the interior nasal passage wall may draw in during inhalation to substantially block the flow of air. Blockage of the nasal passages as a result of malformation, or nasal congestion symptoms of the common cold or seasonal allergies are particularly uncomfortable at night, and can lead to sleep disturbances, irregularities and general discomfort.
In use the external nasal dilator is flexed across the bridge of the nose, extending over and engaging the nasal passage outer wall tissues on each side of the bridge, and held thereto by adhesive. A resilient member (synonymously referred to in the art as a spring, spring member, resilient band, resilient member band, or spring band) extends along the length of the device, embedded within or affixed thereto. When flexed across the bridge of the nose, the resilient member, having resiliency or resilient properties, exerts spring biasing forces extending from the middle of the dilator to its opposite end regions, which urges the nasal outer wall tissues outward, providing dilation and/or stabilization thereto. Stabilized or dilated tissue decreases airflow resistance within the nasal passages, allowing for a corresponding increase in nasal airflow. Increased nasal airflow may have a beneficial effect on nasal congestion, nasal snoring and obstructive sleep apnea.
A portion of the external nasal dilator art is suitable for mass production and commercialization in the consumer market, including devices disclosed in U.S. Pat. Nos. D379513, 6453901, D429332, D430295, D432652, D434146, D437641 and U.S. patent application Ser. Nos. 12/024,763, 12/106,289, 12/402,214, 12/964,746 and 29/380,763, the entire disclosures of which are incorporated by reference herein. Nasal dilators that have heretofore been widely available to consumers through a retail product category referred to generically as nasal strips include devices disclosed in U.S. Pat. Nos. D379513, 5533503, 5546929, RE35408, and 7,114,495.
The preferred thermoplastic material from which external nasal dilator resilient members are fabricated carries a significantly greater cost per unit of measure than other materials typically found in nasal dilator construction. Accordingly, simple resilient member structures, such as one or two rectangular resilient bands having a single thickness prevail in dilator devices that have been successfully commercialized. These resilient members are easily mass produced, extending the entire length of the dilator device so as to be severed at the dilator device ends in a continuous die-cutting process.
A single rectangular resilient member bisected lengthwise into two or three narrower, closely parallel members, each having the same thickness, length and width, is disclosed in the art. A single resilient member having divergent end portions, or multiple resilient member structures where one or more individual members have divergent end portions, are more recent in the art. In each case, the multiple resilient members are positioned adjacent each other and slightly spaced apart, as seen, for example, in U.S. Pat. No. 6,453,901 and U.S. patent application Ser. Nos. 12/024,763 and 12/106,289.
A dynamic relationship exists between dilator design and its efficacy, including resiliency, comfort and useful duration (i.e., the amount of time the device will remain effectively adhered to the skin). To be effective for a majority of users, a nasal dilator must generate from about 15 grams to about 35 grams of resiliency, or spring biasing force. Less than 15 grams may not provide enough stabilization or dilation, while greater than 35 grams would be uncomfortable for most users. The amount of spring biasing force is determined by the type of resilient member material used, its peripheral configuration, its overall width and length, and its thickness.
Nasal dilator resiliency creates primarily peel forces at the device end regions together with some tensile forces that work to disengage the device from the skin. External nasal dilators having design attributes that transform or redirect at least some disengaging peel and tensile forces into shear forces are disclosed in U.S. Pat. Nos. 5,533,503, 6,453,901 (FIGS. 10-11), and in U.S. patent application Ser. Nos. 12/106,289, 12/964,746 and 29/380,763. Shear forces are more easily withstood by adhesives typically used to engage nasal dilators to the skin surface of the nose. Other external nasal dilators, such as those disclosed in U.S. Pat. Nos. 6,543,901, 5,546,929 and RE35408 and U.S. patent application Ser. No. 12/402,214, overcome disengaging peel forces using an island-placed resilient member centrally registered within the device's peripheral edges. Skin-engaging material extends continuously outward beyond the peripheral edges of the resilient member, particularly from the opposite ends thereof, to overcome disengaging peel and tensile forces thereat. Island-placed resilient member structures are traditionally more costly to fabricate and have been less common in mass-produced dilator devices.
U.S. Pat. No. 6,375,667 (Ruch) discloses a nasal dilator having first and second resilient bands secured to first and second end regions of a flexible strip, plus a third resilient band interconnecting the first and second bands. The ends of the third resilient band overlap the inward ends of the first and second resilient bands, respectively, such that the three bands extend in a longitudinal line successively from end to end. U.S. Pat. No. 6,470,883 (Beaudry) discloses a nasal dilator having two stacked rectangular spring laminates (22, 24) that form a leaf spring (20). The upper laminate has a shorter length, but appears to have the same width and thickness as the lower laminate.
There is a continuing need in the art to address nasal dilator disengaging or delaminating peel forces, the dynamic relationship between adhesive engagement and spring biasing forces, and to economically manufacture on a mass scale nasal strip devices having complex resilient member structures of improved efficacy, durational longevity, and comfort. Furthermore, the nasal strip consumer product category has heretofore been dominated by a single brand, creating a pent up demand for innovation, competition, variety and complexity in nasal strip products.